Automotive manufacturers continuously investigate vehicle front end structures that mitigate injuries associated with pedestrian collisions. The vehicle front end structure can have multiple impact areas, including the hood, the grille, the headlamps, the fender, the windshield and the cowl. One exemplary collision may include the lower limbs of the pedestrian first contacting the vehicle bumper, the upper thigh or pelvis hitting the leading edge of the hood, and the head and upper torso impacting the top surface of the hood or the windshield. The hood is typically made of sheet metal, which is a somewhat deformable energy absorbing structure. On the other hand, components underlying the hood in the engine bay and the engine bay support structure itself typically are stiffer and therefore do not absorb much of the energy associated with pedestrian collisions. In this respect, a sufficient gap or clearance between the hood and the engine components can allow the hood to deform and provide a controlled deceleration of the pedestrian's head thus significantly mitigating potential injuries associated with any head impact on the hood.
Multiple challenges may be associated with incorporating a sufficient gap or clearance between the hood and engine components. For instance, the gap or clearance may require a spatial arrangement of the hood and engine components, which can adversely affect aerodynamics and styling requirements for a particular vehicle. In addition, some regions of the hood may be directly supported by stiff support structures without any clearance for deformation of those regions of the hood. Some examples of these regions can include the edges of the hood and the cowl where the hood meets the windshield.
Vehicle front end structures may include modules that use pyrotechnic devices to deploy multiple energy absorbing structures, such as airbags. While these pyrotechnic devices may quickly deploy energy absorbing structures, the devices may be non-repeatable and therefore need to be replaced if they are deployed in response to the false prediction of collisions with pedestrians by the vehicle based pre-crash sensing systems or due to lower speed impacts with non-pedestrian objects thus increasing the cost of such devices.
It would therefore be desirable to provide a vehicle front end structure that can improve pedestrian protection by providing additional clearance from stiff vehicle structures, may be reused if no pedestrian is actually impacted by the vehicle and does not adversely affect aerodynamic performance and styling requirements associated with the vehicle.